Is expert qualification necessary for acceptance?

As a layperson, I would say the following: Before acceptance, the burden of proof lies with the contractor (GU, GÜ, BT). After acceptance, it is reversed. In other words: Go through the house with your acquaintance before acceptance. Point out everything that seems strange to you as a defect. Wait and see how the contractor reacts.

Do not wait until acceptance to report the defects!

Hello Bieber0815,

what you say is correct, but it is not really what I wanted to know. Would I be at a disadvantage compared to a professional appraiser or not? Does a professional appraiser create a reliable assessment during the acceptance, which is then decisive as the basis for withholding part of the remaining payment? (until the subsequent improvement, of course).

If a professional appraiser creates a reliable assessment during the acceptance inspection,

No, how should he? First, everything is closed, you only see superficial things and second, you probably don’t have the right expert with you (insulation expert, but defect on the window. Yeah, great!). So: make sure that three weeks before the acceptance you can inspect the property alone with your expert friend. Inspect thoroughly. Arrange a pre-acceptance appointment with the contractor 14 days before acceptance. There you write down the 30 small issues (scratches, dents, cosmetic issues, cleaning, etc. pp.). By now you should roughly know whether there are critical construction sites or if things have gone rather well. And you can now decide how to proceed.

For the acceptance itself, in my opinion, you mainly need a witness and confident accompaniment so that you don’t get talked over. Everything that seems odd to you goes into the protocol. Period. End of story. You can get the necessary expert later as well.